Windows 7 installation distrupts NIC function and distrupts complete LAN operation
Hi, after installing Windows 7 on a machine that had Windows Server 2003 R2 installed, the complete LAN went berserk. All switches started blinking like crazy, ping times went up from <1ms up to 500ms (measured from different machines). Only after removing the LAN cable from the machine (onboard NIC), the network went back to normal. In fact I installed Windows 7 next to W2k3 server, so booted back into W2k3, now things went even more crazy: the server wouldn't operate over the onboard NIC anymore, with which it worked before just fine in the past 2 years. Installed an old PCI NIC (no drivers available, hoping on Plug-n-Play, but to no avail) and Windows 7 started working...over the onboard NIC! LAN function remained normal. The other day, installed Windows 7 on a machine that had Windows XP installed, and again, LAN went crazy and the PC is unable to communicate over the onboard NIC. Installed the PCI NIC, hoping this would trigger Win7, just like it did on the previous machine, but that trick didn't work on this PC. Both PC's are of different model and make, custom build, both ASUS mobo's, but one is an Intel Core 2 Duo with intel chipset and the other is an AMD oldy with VIA chipset. Forced NIC's to 100Mb full, or auto, didn't work. Both are connected to gigabit switches. I will try to connect them to 10/100Mb switches, see if that works. Any suggestions? Kind regards! EDIT 2010-01-24 START Installed correct drivers for the extra NIC and same problem. Set the onboard NIC to fixed IP and whoppa, working. Found an article that explains that DHCP broadcasts work differently from XP to Vista etc. Didn't change the described setting in the registry yet, but changed to fixed IP and network started working. Removed extra NIC and still working OK. I will try the suggested registry change and report back. Windows Vista cannot obtain an IP address from certain routers or from certain non-Microsoft DHCP servers EDIT 2010-01-24 END
January 24th, 2010 1:43am

Hi, Let's focus on the Windows 7 network issue. Can you write down the detail symptom on Windows 7 machine? Can the Windows 7 machine access other machine or Internet successfully? This issue can occur by incompatible driver or incorrect network settings. Please try the following steps for a test. 1. Download the NIC driver for Windows 7 from manufacturer website and install it for a test. If the issue persists, please try the NIC driver for Windows Vista and install it in Compatibility Mode. 2. Temporarily turn off firewall and then access other network machine or Internet to check the result. 3. Obtain IP address automatically on Windows 7 machine. What's the result? If the issue persists, please run "IPconfig /all" in Command mode and post the result here. Thanks, Novak
Free Windows Admin Tool Kit Click here and download it now
January 29th, 2010 5:05am

Hi Novak, Sorry for the late reply. 1. Download the NIC driver for Windows 7 from manufacturer website and install it for a test. If the issue persists, please try the NIC driver for Windows Vista and install it in Compatibility Mode. Installed Windows 7 using out-of-the-box drivers. This resulted in network problems. Downloaded drivers from manufacturer site and installed thes, still same problem. Added a second NIC (I believe it was a 3Com), still same problem. 2. Temporarily turn off firewall and then access other network machine or Internet to check the result. Disabled firewall, no different result. Still the whole LAN network is operating badly, huge packet loss and all lights on all switches are blinking extremely rapid. 3. Obtain IP address automatically on Windows 7 machine. Automatic IP was on from step 1. If automatic IP is off, all steps do not produce any problem. 4. Turn off DHCP service on Win2k8 machine and turn on Automatic IP on workstation, should fall back to APIPA, what happens then? 5. Turn off DHCP service on Win2k8 machine, turn on DHCP on router appliance and turn on Automatic IP on workstation, what happens then? 6. Test if http://support.microsoft.com/?scid=kb%3ben-us%3b928233&x=21&y=12 makes a difference with DHCP service active on Win2k8 machine. Have to try these, hope to do so today. Will let you know. The steps mentioned by you, were performed when the problems existed, several months ago. In the mean time, lots of patches are installed. So I will retry all steps, to check if the problem has been resolved in the mean time.
June 21st, 2010 10:29am

Hi Novak, Redid steps 1 to 3: Turned off firewall & changed NIC from fixed IP to DHCP, problem arrises; Next changed NIC driver from VIA to Windows driver, rebooted; still same. Changed IP v4 back to fixed and all OK, Windows Update reported newer VIA NIC driver, installed it, all OK, changed IPv4 back to DHCP, same problem back. Windows does fall back to APIPA.. Next I perfromed steps 4, 5 and 6 in a different order than listed above: Did Step 6, but no difference. Did not do step 4. Did step 5: YEP WORKING! When I deactivate the (one and only) DHCP scope on Windows Server 2008 R2 and turn on DHCP in a Thomson Router, the Windows 7 workstation immidiately gets a correct IP and starts working, with latest VIA driver and Firewall turned on. Did step 4: Turned off DHCP on Thomson and see if Windows 7 workstation falls back to APIPA, and it does, after ipconfig /release and /renew, it correctly does APIPA and then uses the alternate configuration I set up. Next, turn Windows DHCP scope back on...what happens next? Same problem back, doesn't get an IP address after /release and /renew.
Free Windows Admin Tool Kit Click here and download it now
July 6th, 2010 12:49pm

Problem solved. The cause was DHCP server on Windows or me or both ;-) I want reservations in DHCP for my workstations and applicances. Wince Windows 2008 R2, DHCP does not allow you to add fixed leases outside a scope. So I had to create a large scope and then make reservations. I also created an exclusion range to prevent the DHCP service to hand out IP addresses amongst the reservations (the reservations are not a consecutive list). For some reason, the reservation was gone in DHCP. I deleted the exclusion list, still nothing, reconciled -> errors reported, but nothing in EventLog, finally the host showed up in DHCP server but with a different IP than expected but marked as a reservation, removed that lease, checked the reservations list, nothing there, added the reservation that used to be there, did an ipconfig /release and /renew an whoppa, finally the workstation got its reservation thru DHCP server. I haven't re-applied the exclusion on the scope. My guess is that DHCP service is a bit unstable. And also, if Windows 7 and the DHCP service can't figure it out correctly, why does my whole LAN go berserk? I can try to sniff some, see what I come up with...just find the time ;-) Thanks for all the help.
July 6th, 2010 1:30pm

This topic is archived. No further replies will be accepted.

Other recent topics Other recent topics